Pulsed driven displays

Abstract

A pulsed driven display comprising an organic light-emitting device, said device comprising an organic layer comprising a semiconductive polymer, said polymer comprising a fluorene or triarylamine repeat unit, the fluorene or triarylamine repeat unit having a group R pendent from the polymer backbone, wherein R has general formula I: where Ar1 represents phenyl or a group comprising napthyl; Ar2 represents phenyl or a group comprising napthyl; R′ represents a substituent group; R″=H or a substituent; n=0, 1, 2 or 3; m=0 or 1; and n′=1 or 2, with the proviso that m=0 if n=0.

The invention claimed is: 
     
       1. A pulsed driven display comprising a passive matrix organic light-emitting device, said device comprising an organic layer comprising a semiconductive polymer, said polymer comprising a fluorene or triarylamine repeat unit, the fluorene or triarylamine repeat unit having a group R pendent from the polymer backbone, wherein R has general formula I: 
       
         
           
           
               
               
           
         
         where Ar 1  represents phenyl or a group comprising napthyl; Ar 2  represents phenyl or a group comprising napthyl; R′ represents a substituent group; R″=H or a substituent; n=0, 1, 2 or 3; m=0 or 1; and n′=1 or 2, with the proviso that m=0 if n=0. 
       
     
     
       2. A display according to  claim 1 , wherein R′ represents a branched C4 to C20 alkyl or alkoxy group. 
     
     
       3. A display according to  claim 2 , wherein R′ represents t-Bu. 
     
     
       4. A display according to  claim 1 , wherein when n′=1 and Ar 2  represent phenyl, R′ is located at the para position. 
     
     
       5. A display according to  claim 1 , wherein when n′=2 and Ar 2  represent phenyl, R′ are located at the meta positions. 
     
     
       6. A display according to  claim 1 , wherein the polymer comprises a fluorene repeat unit having general formula VI: 
       
         
           
           
               
               
           
         
         where each R independently is as defined in any one of the preceding claims. 
       
     
     
       7. A display according to  claim 1 , wherein the polymer comprises a triarylamine repeat unit comprising a triphenylamine. 
     
     
       8. A display according to  claim 7 , wherein the triarylamine repeat unit has general formula XIVa: 
       
         
           
           
               
               
           
         
       
     
     
       9. A display according to  claim 7 , wherein the triarylamine repeat unit has general formula XIVb: 
       
         
           
           
               
               
           
         
       
     
     
       10. A display according to  claim 1 , wherein the semiconductive polymer is blue light-emitting. 
     
     
       11. A display according to  claim 1 , wherein the semiconductive polymer is hole transporting. 
     
     
       12. A display according to  claim 1 , wherein the semiconductive polymer has at least one further repeat unit selected from the group consisting of 1,4-phenylene repeat units; indenofluorene repeat units; spirofluorene repeat units; 2,7-linked fluorene repeat units; triarylamine repeat units; and heteroarylene repeat units. 
     
     
       13. A method for preparing a display according to  claim 1 , comprising depositing the semiconductive polymer from solution to form a layer. 
     
     
       14. A pulsed driven display according to  claim 1 , wherein n′=2 and R′ represents a branched C4 to C20 alkyl or alkoxy group comprising a tertiary carbon atom.